Flat far field lenses and reflectors

Abstract

We present a flat lens design that provides focusing with no aberration. By profiling the refractive index of the lens to generate a spherical wavefront at the exit side of the lens, the transmitted fields converge at a specified focal point. The focusing is achieved using primarily the dispersion phenomenon. We show through numerical examples that focusing without aberration can be achieved at a specific frequency and that focusing is possible over a narrow range of frequencies providing that the dispersion is minimal. Additionally, we show that the same principle used to design the lens can be used to design flat reflectors with a focal point focusing.